In one cold forming process for forming splines or teeth in cylindrical workparts, the workpart is rotatably mounted between a pair of slidable toothed racks or dies. The racks are slid past the workpart in opposite directions and are spaced apart so as to pressure form tooth shapes in the workpart as they are slid therepast. Such a process is well known.
It has been common in the past to machine each rack body from a bar or billet of high speed steel such as M2 steel. The machined rack body is then subjected to a high temperature solution anneal or hardening treatment (e.g. 2050.degree. F.) followed by multiple lower temperature tempering treatments (e.g. 1025.degree.-1045.degree. F.) to develop the required high hardness (R.sub.c 60-62) in the rack body for the pressure forming operation. Thereafter, sections of forming teeth are precision ground into the rack. When the toothed sections of the rack have worn out of tolerance through use, the rack in the past has been reground to provide new toothed sections. However, there is a point at which insufficient stock is left for regrinding and continued use of the rack and the rack must be scrapped. The portion that must be discarded is oftentimes approximately 50% of the original rack bulk and discarding this material is quite costly, given the fact that it is expensive high speed steel. The Blue U.S. Pat. 4,028,921 issued June 14, 1977 discloses a tooth-forming rack comprising a plurality of high speed steel toothed inserts releasably mounted by cap screws to an elongated insert holder member made of less expensive carbon steel. When a particular toothed insert becomes worn beyond tolerance, it is removed from the insert holder by unscrewing the cap screws and thrown away. A new insert is then attached by the cap screws.